<template>
    <div>
        <div :class="['one',show?'two':'']">Hello world</div>
    </div>
</template>

<script>
    export default {
        data() {
            return {
                show:true
            }
        },
    }
</script>

<style scoped>
    .one{
        text-decoration-line: line-through;
    }
    .two{
        font-size: 30px;
        color: aqua;
    }
</style>